Here is just a few possibilities to consider:
If the file is larger than 2mb (2,048K), check with the recipient before sending to ensure that he/she will be able to receive it. Some Internet Service Providers place restrictions on message sizes.
Do not change the extension of the file. This extension (for example, .doc for Word documents, .xls for Excel spreadsheets) is used by Windows 95 to determine what program was used to create the file, and it also makes it easier for the recipient to know what type of file you have sent.
When sending an attachment, be specific when indicating what type of document is attached. If you know the software program and its version, include that in the message
Note: You may find it necessary to zip or compress the files.
Outlook Express Tips and Trickshttp://www.5starsupport.com/info/outlook-e...htm#attachments
The above site is excellent for using Outlook Express with a ton of info.